V4l2 fails when attempting a second capture

[André Moreira]

I am trying to capture video using this card: ​https://www.ebay.com/itm/1080P-60FPS-USB-3-0-HD-HDMI-Video-Capture-Card-Box-for-Windows-Mac-Linux-/263257786337?hash=item3d4b6307e1

The kernel driver is uvcvideo. The first capture is ok, everything works fine, but the second attempt fails with this information: Dequeued v4l2 buffer contains corrupted data (0 bytes). Then, only audio is captured.

Using VLC, I can watch video from it no matter how many times I reopen the program.

I can successfully capture video again if I reload the module with the command bellow:

sudo modprobe -v -r uvcvideo && sudo modprobe -v uvcvideo

Or if I reser the card with this:

echo 0 > /sys/bus/usb/devices/4-3/authorized
echo 1 > /sys/bus/usb/devices/4-3/authorized

Here the output of ffmpeg:

ffmpeg version N-91127-g411f7141a3 Copyright (c) 2000-2018 the FFmpeg developers
  built with gcc 7 (Ubuntu 7.3.0-16ubuntu3)
  configuration: --enable-nonfree --disable-shared --enable-nvenc --enable-cuda --enable-cuvid --enable-pthreads --extra-cflags=-I/usr/local/cuda-9.0/include --extra-ldflags=-L/usr/local/cuda-9.0/lib64
  libavutil      56. 18.102 / 56. 18.102
  libavcodec     58. 19.102 / 58. 19.102
  libavformat    58. 15.100 / 58. 15.100
  libavdevice    58.  4.100 / 58.  4.100
  libavfilter     7. 24.100 /  7. 24.100
  libswscale      5.  2.100 /  5.  2.100
  libswresample   3.  2.100 /  3.  2.100
Guessed Channel Layout for Input Stream #0.0 : stereo
Input #0, alsa, from 'hw:2,0':
  Duration: N/A, start: 1526757005.217295, bitrate: 1536 kb/s
    Stream #0:0: Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
[video4linux2,v4l2 @ 0x5646abe4c400] Dequeued v4l2 buffer contains corrupted data (0 bytes).
Input #1, video4linux2,v4l2, from '/dev/video0':
  Duration: N/A, start: 0.000000, bitrate: 995328 kb/s
    Stream #1:0: Video: rawvideo (YUY2 / 0x32595559), yuyv422, 1920x1080, 995328 kb/s, 30 fps, 30 tbr, 1000k tbn, 1000k tbc
Stream mapping:
  Stream #1:0 -> #0:0 (rawvideo (native) -> h264 (h264_nvenc))
  Stream #0:0 -> #0:1 (pcm_s16le (native) -> aac (native))
Press [q] to stop, [?] for help
[video4linux2,v4l2 @ 0x5646abe4c400] Dequeued v4l2 buffer contains corrupted data (0 bytes).
    Last message repeated 30 times
Output #0, mpegts, to '/tmp/out.ts':
  Metadata:
    encoder         : Lavf58.15.100
    Stream #0:0: Video: h264 (h264_nvenc) (High 4:4:4 Predictive), yuv444p(progressive), 1920x1080 [SAR 1:1 DAR 16:9], q=19-50, 8000 kb/s, 30 fps, 90k tbn, 30 tbc
    Metadata:
      encoder         : Lavc58.19.102 h264_nvenc
    Side data:
      cpb: bitrate max/min/avg: 12000000/0/8000000 buffer size: 16000000 vbv_delay: -1
    Stream #0:1: Audio: aac (LC), 48000 Hz, stereo, fltp, 128 kb/s
    Metadata:
      encoder         : Lavc58.19.102 aac
frame=    3 fps=0.0 q=21.0 size=      10kB time=00:18:06.70 bitrate=   0.1kbits/
frame=    3 fps=3.0 q=21.0 size=      19kB time=00:18:06.70 bitrate=   0.1kbits/
frame=    3 fps=2.0 q=21.0 size=      28kB time=00:18:06.70 bitrate=   0.2kbits/
frame=    3 fps=2.0 q=21.0 Lsize=     182kB time=00:18:06.76 bitrate=   1.4kbits/s speed= 709x

[André Moreira]

ffplay works.